The invention relates to reading apparatus for the simultaneous detection of all the magnetic states previously recorded on a determined length of a magnetic strip arranged on a substrate and, more particularly, on a textile one.
The products which are sold, especially in the field of food products, often bear "labels" or "tags" consisting of "bar codes", which define some features of the products, such as an identification number in a nomenclature, the latest date of use, etc. . . Such tags are read by an appropriate optical device at the pay-desk of the store and the data thus obtained are used to determine, for instance, the price of the sold product and to update the stock on hand.
Generally, such tags are directly printed on the product packing, which packing exhibits some degree of rigidity, thus facilitating the error-proof reading of the bar codes of the tag.
Such tags may also be used for clothes, but in this case they must be placed on the wrapping in order to provide said rigidity, but, since the wrapping may be easily separated from the garment, which may lead to errors and to fraud.
It is therefore important that the tag be placed on the garment itself in a non detachable way but, then, it results in a difficult reading of the bar codes on the soft substrate, that is the textile of the garment.
Besides, it is rather easy to reproduce such tags since bar codes are visible by definition, which makes it possible to modify, in particular, the identification, the price and the mark.
Consequently, it has been suggested that such tags be made as magnetic strips arranged on a flexible substrate and then encoded using binary magnetic states.